Pulmonary Hypertension

Pulmonary hypertension refers to an abnormal increase in blood pressure in the pulmonary arteries. This pressure level places an extra burden on the heart, which has to work harder than usual to pump blood to the lungs. Pulmonary hypertension is diagnosed when the mean pulmonary artery pressure at rest is equal to or greater than 25 mmHg.

Based on the origin of the condition, pulmonary hypertension is classified into five types:

• Group 1: Pulmonary arterial hypertension (PAH).
• Group 2: Pulmonary hypertension associated with left heart disease.
• Group 3: Pulmonary hypertension associated with respiratory diseases or hypoxemia.
• Group 4: Chronic thromboembolic pulmonary hypertension.
• Group 5: Pulmonary hypertension of unclear or multifactorial causes.

According to left ventricular filling pressure values, it is classified as:

• Precapillary pulmonary hypertension: Normal filling pressure, with a value equal to or less than 15 mmHg. This includes groups 1, 3, 4, and some cases of group 5.
• Postcapillary pulmonary hypertension: Filling pressure greater than 15 mmHg. This includes group 2 and some cases of group 5.

Symptoms

Pulmonary hypertension symptoms develop slowly and may go unnoticed for months or even years. They worsen as the disease progresses. The most common symptoms include:

• Dyspnea: Shortness of breath that initially occurs during exertion and later at rest.
• Syncope during or after exertion.
• Chest pain.
• Fatigue.
• Rapid heart rate and palpitations.
• Peripheral edema: Swelling due to fluid retention in the ankles and legs.

In the advanced stages of severe pulmonary hypertension and heart damage, the following symptoms appear:

• Jugular vein distention: Prominent jugular vein in the neck.
• Cyanosis: Bluish skin discoloration due to lack of oxygen in the blood.
• Clubbing: Painless deformity of the fingertips and nails.
• Ascites: Fluid accumulation in the abdomen.

Causes

Blood pressure increases because the arterial walls narrow, become inflamed, and thicken, slowing blood flow to the lungs. This arterial deterioration has various causes depending on the type of pulmonary hypertension:

Pulmonary arterial hypertension (PAH):

• Hereditary mutation in a specific gene.
• Congenital heart diseases, such as Eisenmenger syndrome.
• Use of certain medications or toxic substances, such as amphetamines.
• Other diseases, including chronic liver disease, portal hypertension, viral infections, or connective tissue diseases such as scleroderma or lupus.
• Sometimes, the cause is unknown (idiopathic pulmonary arterial hypertension).

Pulmonary hypertension associated with left heart disease:

• Left heart failure.
• Mitral or aortic valve disease.

Pulmonary hypertension associated with respiratory diseases or hypoxemia:

• Combination of fibrosis and pulmonary emphysema.
• Chronic obstructive pulmonary disease (COPD).
• Interstitial lung disease.
• Sleep apnea.

Chronic thromboembolic pulmonary hypertension:

• Blood clots in the lungs.
• Tumors obstructing the pulmonary artery.

Pulmonary hypertension of unclear or multifactorial causes:

• Blood disorders, such as polycythemia vera and essential thrombocythemia.
• Inflammatory disorders, such as sarcoidosis.
• Metabolic disorders.
• Kidney disease.

Risk Factors

Risk factors that increase the likelihood of developing pulmonary hypertension include:

• Age: The risk increases with aging, though idiopathic pulmonary hypertension is more common in young adults.
• Family history of pulmonary hypertension or clotting disorders.
• Overweight.
• Smoking.
• Use of certain medications: weight-loss drugs, chemotherapy agents, and stimulants such as amphetamines or cocaine.
• Exposure to asbestos or specific parasites.
• Consumption of adulterated rapeseed oil.
• Blood clotting disorders.

Complications

Possible complications of pulmonary hypertension include:

• Cor pulmonale: Enlargement and thickening of the right ventricle due to increased workload (the ventricle dilates to hold more blood).
• Right heart failure: Occurs when the right ventricle's compensation is insufficient for normal heart function.
• Blood clots in the pulmonary arteries.
• Pulmonary hemorrhage, which can be fatal.
• Sudden death due to arrhythmias.
• In pregnant women, pulmonary hypertension poses a life-threatening risk to both the mother and the baby.

Prevention

Preventing pulmonary hypertension involves managing its risk factors:

• Maintaining a healthy weight.
• Not smoking.
• Avoiding stimulant drugs, certain medications, and adulterated rapeseed oil.

What Specialist Treats Pulmonary Hypertension?

Pulmonary hypertension is diagnosed and treated by specialists in cardiology and cardiovascular surgery.